Totally a money grab by the LAPD and the city. Excerpts the article

Bandit taxi enforcement ramped up in 2006 after The Board of Taxicab Commissioners hammered out a plan with the cab companies. The deal called for a $30 monthly fee imposed on each taxicab to raise money for the stings[...]

But, city records show, the deal would only stand if the fee could ultimately be passed on to passengers. Fares hiked up 20 cents[...]

Elvin Galindo, an investigator at the Los Angeles Department of Transportation, said cabbies were tired of losing out on fares to drivers who sidestepped city regulations and fees[...]

Galindo insisted that it was not a conflict of interest for the City of Los Angeles to take money from the taxi companies to fund stings that now arrest their top competitors[...]

The L.A. Department of Transportation impounded her car after the sting, and it cost her about $1,000 to spring it out.

Pretty crazy that they voluntarily offered up this information while denying it has any conflict of interest with how they spend their resources